Helleborus plant named ‘COSEH 4000’

ABSTRACT

A new and distinct cultivar of  Helleborus  plant named ‘COSEH 4000’, characterized by its upright and mounding plant habit; uniform and freely flowering habit; dark green-colored leaves; freely and early flowering habit; single white-colored flowers with red purple-colored margins; and good garden performance.

Botanical designation: Helleborus×ericsmithii×Helleborus×hybridus.

Cultivar denomination: ‘COSEH 4000’.

BACKGROUND OF THE INVENTION

The present invention relates to a new and distinct cultivar of Helleborus plant, botanically known as Helleborus×ericsmithii×Helleborus×hybridus and hereinafter referred to by the name ‘COSEH 4000’.

The new Helleborus plant is a product of a planned breeding program conducted by the Inventor in Glandorf, Germany. The objective of the breeding program was to create new uniform Helleborus plants with unique and attractive plant habit, leaf and flower coloration and resistance to pests common to Helleborus plants.

The new Helleborus plant originated from a cross-pollination conducted by the Inventor in Glandorf, Germany in November, 2010 of an unnamed selection of Helleborus×ericsmithii, not patented, as the female, or seed, parent with an unnamed seedling selection of Helleborus×hybridus, not patented, as the male, or pollen, parent. The new Helleborus plant was discovered and selected by the Inventor as a single flowering plant from within the progeny of the stated cross-pollination grown in a controlled greenhouse environment in Glandorf, Germany in December, 2012.

Asexual reproduction of the new Helleborus plant by divisions in a controlled environment in Glandorf, Germany since February, 2013 has shown that the unique features of this new Helleborus plant are stable and reproduced true to type in successive generations.

SUMMARY OF THE INVENTION

Plants of the new Helleborus have not been observed under all possible combinations of environmental conditions and cultural practices. The phenotype may vary somewhat with variations in environmental conditions such as temperature and light intensity without, however, any variance in genotype.

The following traits have been repeatedly observed and are determined to be the unique characteristics of ‘COSEH 4000’. These characteristics in combination distinguish ‘COSEH 4000’ as a new and distinct Helleborus plant:

-   -   1. Upright and mounding plant habit.     -   2. Uniform and freely flowering habit.     -   3. Dark green-colored leaves.     -   4. Freely and early flowering habit.     -   5. Single white-colored flowers with red purple-colored margins.     -   6. Good garden performance.

Compared to plants of the female parent selection, plants of the new Helleborus and the female parent selection differ primarily in flower color as plants of the female parent selection have creamy white to pink-colored flowers. Compared to plants of the male parent selection, plants of the new Helleborus are more uniform and are more freely flowering.

Plants of the new Helleborus can be compared to plants of Helleborus niger×Helleborus lividus ‘COSEH 710’, disclosed in U.S. Plant Pat. No. 21,063. In side-by-side comparisons, plants of the new Helleborus differ primarily from plants of ‘COSEH 710’ in the following characteristics:

-   -   1. Plants of the new Helleborus have smaller flowers than plants         of ‘COSEH 710’.     -   2. Plants of the new Helleborus flower earlier than plants of         plants of ‘COSEH 710’.     -   3. Plants of the new Helleborus and ‘COSEH 710’ differ in flower         color as plants of ‘COSEH 710’ have light green-colored flowers         with reddish pink overtones.

BRIEF DESCRIPTION OF THE PHOTOGRAPHS

The accompanying colored photographs illustrate the overall appearance of the new Helleborus plant showing the colors as true as it is reasonably possible to obtain in colored reproductions of this type. Colors in the photographs may differ slightly from the color values cited in the detailed botanical description which accurately describe the colors of the new Helleborus plant.

The photograph on the first sheet is a side perspective view of a typical flowering plant of ‘COSEH 4000’ grown in a container.

The photograph on the second sheet is a close-up view of a typical flower of ‘COSEH 4000’.

DETAILED BOTANICAL DESCRIPTION

The aforementioned photographs and following observations, measurements and values describe plants grown during the autumn in 15-cm containers in a glass-covered greenhouse in Glandorf, Germany and under cultural practices typical of commercial Helleborus production. During the production of the plants, day temperatures ranged from 12° C. to 32° C. and night temperatures ranged from 3° C. to 18° C. Plants were 14 months old when the photographs and the description were taken. In the following description, color references are made to The Royal Horticultural Society Colour Chart, 2015 Edition, except where general terms of ordinary dictionary significance are used.

-   Botanical classification: Helleborus×ericsmithii×Helleborus×hybridus     ‘COSEH 4000’. -   Parentage:     -   -   Female, or seed, parent.—Unnamed selection of             Helleborus×ericsmithii, not patented.         -   Male, or pollen, parent.—Unnamed seedling selection of             Helleborus×hybridus, not patented. -   Propagation:     -   -   Type.—By tissue culture.         -   Time to initiate roots, winter.—About two months at             temperatures about 12° C.         -   Time to produce a rooted young plant, winter.—About six             months at temperatures ranging from 4° C. to 15° C.         -   Root description.—Thick to thin, fleshy; typically white to             brown in color, actual color of the roots is dependent on             substrate composition, water quality, fertilizer type and             formulation, substrate temperature and physiological age of             roots.         -   Rooting habit.—Sparse. -   Plant description:     -   -   Plant and growth habit.—Herbaceous perennial; upright and             mounding plant habit with flowers held above and beyond the             foliar plane; plant shape, roughly flattened globular;             moderately vigorous growth habit; moderate growth rate.         -   Plant height, soil level to top of foliar plane.—About 20             cm.         -   Plant height, soil level to top of flowers.—About 31.8 cm.         -   Plant diameter (area of spread).—About 38.4 cm. -   Leaf description:     -   -   Arrangement.—Leaves arranged in a basal rosette; leaves             palmately compound with typically five to seven leaflets per             leaf.         -   Leaf length.—About 16.6 cm.         -   Leaf width.—About 18.6 cm.         -   Leaflet length.—About 11.2 cm.         -   Leaflet width.—About 5.7 cm.         -   Leaf shape.—Palmate; reniform in outline.         -   Leaflet shape.—Ovate, elliptic and obovate.         -   Leaflet apex.—Apiculate.         -   Leaflet base.—Attenuate.         -   Leaflet margin.—Serrate; undulate.         -   Leaflet texture and luster, upper surface.—Smooth, glabrous;             slightly rugose; leathery; glossy.         -   Leaflet texture and luster, lower surface.—Smooth, glabrous;             slightly rugose; leathery; slightly glossy.         -   Leaflet venation pattern.—Pinnate.         -   Leaflet color.—Developing leaflets, upper surface: Close to             N137A. Developing leaflets, lower surface: Close to 147B.             Fully developed leaflets, upper surface: Close to darker             than between 139A and N189A; venation, close to 147B. Fully             developed leaflets, lower surface: Close to 143B to 143C;             venation, close to 152A.         -   Petioles.—Length: About 11.5 cm. Diameter: About 5 mm.             Strength: Strong. Texture and luster, upper and lower             surfaces: Smooth, glabrous; glossy. Color, upper and lower             surfaces: Close to N148A, heavily tinged and speckled with             close to N199B. -   Flower description:     -   -   Flower shape and habit.—Single rotate flowers arranged             solitary or in panicles; freely and uniform flowering habit             with about ten flowers per inflorescence and about 40             flowers developing per plant; flowers facing outwardly to             slightly nodding.         -   Fragrance.—None detected.         -   Natural flowering season.—Plants begin flowering about ten             months after planting; plants flower from autumn into winter             in Germany.         -   Flower longevity on the plant.—About ten days; flowers not             persistent.         -   Flower buds.—Length: About 2 cm. Diameter: About 1.3 cm.             Shape: Ovate. Texture and luster: Glabrous; matte. Color:             Close to between 145D and 150D.         -   Inflorescence height.—About 31.6 cm.         -   Inflorescence diameter.—About 30.8 cm.         -   Flower diameter.—About 8 cm.         -   Flower depth (height).—About 2.6 cm.         -   Petals.—Transformed into nectaries.         -   Sepals.—Quantity and arrangement: About five, arranged in a             single whorl. Length: About 4 cm. Width: About 4 cm. Shape:             Broadly ovate. Apex: Obtuse. Base: Cuneate. Margin: Entire.             Texture and luster, upper and lower surfaces: Glabrous;             matte. Color: When opening, upper surface: Close to NN155A             to NN155B. When opening, lower surface: Close to NN155A             tinged with close to 157D and 74B. Fully opened, upper             surface: Close to N155C; towards the margins, heavily tinged             with close to between 64A and 70A; with development, color             becoming closer to 147B and margins, tinged with close to             N77A. Fully opened, lower surface: Close to 184B and 184C;             towards the margins, heavily tinged with close to between             64A and 70A; with development, color becoming closer to             slightly darker than N77A.         -   Flower bracts.—Quantity per flower: Typically two. Length:             About 6.1 cm. Width: About 3.4 cm. Shape: Ovate. Apex:             Acute. Base: Broadly cuneate. Margin: Entire; distally,             occasionally serrated; undulate. Color, upper surface:             Slightly darker than close to between NN137A and 147A.             Color, lower surface: Close to 146A to 146B.         -   Peduncles.—Length: About 26.8 cm. Diameter: About 9 mm.             Aspect: About 25° from vertical. Strength: Strong. Texture             and luster: Glabrous; slightly glossy. Color: Close to 144             A, speckled with close to 177B.         -   Pedicels.—Length: About 4 cm. Diameter: About 3 mm. Aspect:             About 25° from peduncle axis. Strength: Moderately strong.             Texture and luster: Glabrous; glossy. Color: Close to 144B,             speckled and tinged with close to 152A and 152B.         -   Reproductive organs.—Stamens: Quantity per flower: About 80.             Filament length: About 1.8 cm. Filament color: Close to             NN155D. Anther shape: Reniform; basifixed. Anther size:             About 1.75 mm by 2 mm. Anther color: Close to 2C. Pollen             amount: Scarce. Pollen color: Close to 2D. Pistils: Quantity             per flower: About four to seven. Pistil length: About 1 cm.             Stigma diameter: About 0.3 mm. Stigma shape: Club-shaped.             Stigma color: Close to 155A. Style length: About 9.5 mm.             Style color: Close to 63D. Ovary color: Close to 150D.             Nectaries (transformed petals): Quantity per flower:             About 13. Length: About 1.2 cm. Diameter: About 3.5 mm.             Shape: Tubular, flattened. Texture and luster, inner             surface: Smooth, glabrous; matte. Texture and luster, outer             surface: Smooth, glabrous; glossy. Color, immature, inner             and outer surfaces: Close to N144D; towards the apex, close             to 154B. Color, mature, inner and outer surfaces: Close to             146D; towards the apex, close to 12A.         -   Seeds and fruits.—Seed and fruit development have not been             observed on plants of the new Helleborus. -   Garden performance: Plants of the new Helleborus have been observed     to have good garden performance and to tolerate rain, wind and to be     suitable for USDA Hardiness Zones 5 through 9. -   Pathogen & pest resistance: Plants of the new Helleborus have not     been observed to be resistant to pathogens and pests common to     Helleborus plants. 

It is claimed:
 1. A new and distinct Helleborus plant named ‘COSEH 4000’ as illustrated and described. 